1. Field of the Invention
The invention relates to a sealing device for the sealing of at least one zone of underpressure or overpressure adjoining a moved surface in a paper making machine. The sealing device includes at least one sealing element disposed opposite the moved surface. Such a sealing device is known, e.g., from DE-A-197 51 283 (see FIG. 15).
2. Discussion of Background Information
Such sealing devices are used in practice both in the former part and in the press part and/or the dryer part of a respective paper machine, where they can be used in, among other things, suction rolls or blow rolls. For instance, as a rule, suction rolls have fixed interior suction boxes which form, e.g., adjustable zones having at least one pressure level, with the sealing of the pressure zones or vacuum zones taking place in the wire travel direction by sealing strips, which as a rule extend at least substantially over the whole roll length.
As a rule, sealing strips having a continuous straight runoff edge are used for sealing the vacuum in suction roll types. However, the vacuum in the roll perforation breaks down abruptly at such a runoff edge of the sealing strip running off in the wire travel direction, which produces an extremely high development of noise and results in a clearly audible, shrill so-called “suction roll whistle”.